The background art shows examples of papermaking processes utilizing a foraminous forming fabric, thermal predrying of the fibrous web, and a prewrap of the Yankee dryer with the web prior to imprinting effected between a pressure roll and a Yankee drum dryer. Examples of these can be seen in U.S. Pat. No. 3,301,746 issued to L. H. Sanford et al. on Jan. 31, 1967; U.S. Pat. No. 3,994,771 issued to G. Morgan, Jr. et al. on Nov. 30, 1976; and U.S. Pat. No. 3,926,716 issued to G. A. Bates on Dec. 16, 1975.
U.S. Pat. No. 4,102,737 issued to W. J. Morton on July 25, 1978 discloses a papermaking process using a foraminous forming fabric, predrying of a web on the foraminous forming fabric, and pretensioning of a forming fabric against the Yankee dryer prior to running through the nip of a pressure roll and the Yankee dryer surface.
Papermaking processes using a papermaking felt and two rolls pressing the felt two separate times against the Yankee dryer are disclosed in U.S. Pat. No. 3,691,010 issued to K. A. Krake on Sept. 12, 1972 and U.S. Pat. No. 3,560,333 issued to D. C. Douglas et al. on Feb. 2, 1971. In U.S. Pat. No. 2,209,758 issued to E. E. Berry on July 30, 1940, a papermaking process utilizing a papermaking felt is taught where the felt is contacted with a Yankee dryer drum in the nip of the drum with a pressure roll and the felt is postwrapped around the Yankee dryer drum.
In U.S. Pat. No. 3,526,574 issued to E. D. Bleacher et al. on Sept. 1, 1970, a process to make delicate papers is disclosed utilizing a papermaking felt and a Yankee dryer. In Bleacher, the papermaking felt forms a sandwich against the Yankee dryer containing the paper web either prior to running through the nip of the pressure roll or after running through the nip between the Yankee dryer and the pressure roll.
A papermaking process showing a papermaking felt running through the nip of a first pressure roll and a Yankee dryer, wrapped around the surface of a Yankee dryer and run through the nip of a second pressure roll and a Yankee dryer is disclosed in U.S. Pat. No. 1,695,972 issued to E. A. Ohlin et al. on Dec. 18, 1928 and U.S. Pat. No. 3,891,500 issued to Kankaanpaa on June 24 1975.